A known electronic device comprising a mobile communication terminal (e.g., a smart phone) includes a large screen touch-type display device and a high pixel resolution camera lens assembly to capture still pictures and moving pictures in addition to supporting a basic communication function. In addition, the mobile communication terminal plays back multimedia content such as music and moving pictures and connects to a network for web surfing. A known mobile communication terminal is equipped with a high-performance CPU and performs various advanced functions. A known mobile communication terminal is coupled to external devices selectively or mandatorily for particular functions using miniaturized external devices and associated interfaces. For example, a memory card external device expands storage space and a subscriber identification module card (so-called a “SIM” card) external device is detachably mounted such that a plurality of users requiring different authentication may use one electronic device. A SIM card external device is implemented as a type of card to facilitate use with a mobile communication terminal and to minimize needed mounting space. The SIM card is mounted in a socket within the device through an external port disposed at a selected location to enable access to mobile communication.
A SIM card stores subscriber information of a mobile communication terminal as well as system related information and is used for a CDMA type and other types of mobile wireless terminal. A SIM card is mounted in an electrical socket having a plurality of contact pads with predetermined size. A SIM card has a cut-out portion formed by cutting out one corner portion to guide a user in correct insertion of the SIM card into a terminal. A SIM card has easily recognized contact pads on one surface facilitating correct insertion of a card. However, since a SIM card is miniaturized and difficult to pick up by hand, a user may insert the SIM card into a socket in an erroneous opposite direction ignoring the cut-out portion of the SIM card, preventing operation of the mobile communication terminal or, causing malfunction. In addition, it becomes difficult for a user to separate a small SIM card from a socket for correct re-insertion. A system according to invention principles addresses these deficiencies and related problems.